Photography: AMERICAN BEAUTY: Mary Ellen Mark

A SUPERB SHOW THAT LOOKS BENEATH THE SURFACE

Good pictures get to the point. It's great pictures that don't. Sometimes they have no point to get to. They don't try to simplify matters but to complicate them, to add nuance upon nuance and keep all judgments suspended. In the Mary Ellen Mark show that opened this month at the Philadelphia Museum of Art, there are dozens of good pictures. There are some great pictures too.

For Mark, the Philadelphia show, which runs through Aug. 6 and then moves to Fort Wayne, Ind., New York City and San Francisco, is a homecoming. In the early 1960s she studied painting and...